Braking balance needs to be added to the cars. It's unavailable in Sport Mode.
Also this ->
https://en.wikipedia.org/wiki/Trail_braking
My sensitivity is set to 10.
Have a look at the steering dot when turning. That shows the actual amount of input that the car is getting versus what you are giving it. I can have the controller at full input, but the car doesn't care. The game is over filtering my input, and since I can do nothing more to increase my steering angle, the game is forcing me to drive slower.
This isn't fun. What's the point? I can handle being at the back of the pack because of my own mistakes or inability, but if the game is handicapping me and filtering my input, then I'm just fighting the game.